The Deltoid muscle is a triangular-shaped muscle located at the shoulder joint. It is responsible for controlling the movement of the arm in abduction, flexion, and extension. Like other muscles in your body, deltoid muscles in your shoulder contain elastic fibers. These fibers make the muscles flexible, so they can perform lots of movements. Working out the Deltoid muscle is key for stabilizing your shoulder joint and for building a better upper body. Strengthening your Deltoid not only gives y